长期不同施肥处理对设施土壤团聚体组成及其稳定性的影响

通过设施土壤长期定位,试验研究了不同施肥处理对土壤团聚体含量、分布及其稳定性的影响。结果表明,有机肥处理的设施土壤水稳性团聚体的优势粒级均为0.125～0.250mm,而未施用有机肥处理的设施土壤水稳性团聚体的优势粒级均为0.053～0.125mm。设施土壤中>0.25mm粒级水稳性团聚体含量明显低于<0.25mm粒级水稳性团聚体。在>0.125mm的粒级中,有机肥(AN0)及其有机无机肥配施(ANPK)处理土壤水稳性团聚体比重均高于无机肥(BNPK)及其不施用肥料(BN0)处理土壤。长期施用有机肥具有促进水稳性微团聚体向水稳性大团聚体形成的趋势。设施土壤团聚体稳定指数大小依次为:ANPK>AN0>BNPK>BN0。分形维数D、几何平均直径GMD、平均重量直径MWD均适用于该设施土壤水稳性团聚体评价。

Effects of Long-term Different Fertilizations on Composition and Stability of Soil Aggregates in a Greenhouse Soil

The effects of different fertilizations on the content,distribution,and stability of soil aggregates were studied by a long-term fertilization experiment in a greenhouse soil.Results showed that the greatest size of wet stable aggregates of the greenhouse soil with organic fertilizer was in the 0.125~0.25 mm fraction,while the greatest size of wet stable aggregates of the greenhouse soil without organic manure was in the 0.053~0.125 mm fraction.The content of wet stable aggregates in >0.25 mm fraction was significantly lower than that in the <0.25 mm fraction.In the >0.125 mm fraction,the contents of wet stable aggregates with organic fertilization(AN0) and the combined organic and inorganic fertilization(ANPK) were higher than those with(BNPK) and without(BN0) inorganic fertilizer.The long-term application of organic fertilizer could enhance the formation of wet stable aggregates from macro-aggregates to micro-aggregates.The stability index of soil aggregates in different treatments was in the order of ANPK > BNPK > AN0 > BN0.Fractal dimension(D),geometric mean diameter(GMD),and mean weight diameter(MWD) were all suitable to evaluating wet stable aggregates of the greenhouse soil.